26 research outputs found
Use of Probiotics as Growth Promoters and Immunostimulators in Fingerlings of Cyprinid Fish Species
Intensive aquaculture production has required the development of an individualâs resistance to disease rather than depending upon antibiotics or chemotherapeutics. The role of gastrointestinal microflora in disease resistance has been established in many fish species, which has led to the concept of manipulating gastrointestinal microflora for better health management. A number of studies has been conducted in different fish species with various useful microorganisms called âprobioticsâ to amplify gastrointestinal microflora to fight against various infectious diseases. Probiotics are beneficial microorganisms which protect the host from diseases. Probiotic protection can be achieved by various mechanisms. Most probiotics used in aquaculture belong to the lactic acid bacteria, the genus Bacillus, the photosynthetic bacteria, the yeast, notwithstanding other genera and species have also been used. The immunostimulatory effect of probiotics has been established in many fish species, but their direct involvement in the immune response is not well established. It has also been proven that the application of probiotics in aquaculture has beneficial effects on growth of fish as well as on the environment. At present, data about the efficacy of probiotics in commercial aquaculture of Serbia is still lacking. This review discusses mainly the studies and applications about effects, problems and perspectives of probiotics used in fingerlings of cyprinid fish species, and highlights immunostimulatory effects and growth promotion effects of commercial probiotic products. In the present paper the results that show positive influence of probiotics in cyprinides nutrition on production performance and immune system are summarized. Special accent is given to criteria for proper selection of probiotics in cyprinides production
Antibiotics Residues as Limiting Factor of Honey Quality
Residues of veterinary drugs represent a significant risk to the health of honey consumers. Antibiotics can get into honey by using the antibiotics for treatment and prevention of bees diseases but also through the plant nectar and pollen. In Serbia, the use of antibiotics in beekeeping for bacterial diseases treatment is prohibited and accordingly there is no prescribed maximum permissible concentration for them in honey. The aim of this paper is to monitor the presence of antibiotic residues in honey which necessarily indicate their illegal and uncontrolled use. The presence of antibiotic residues in honey was screened for microbiological method "Modified method 4 plates" (EUR 15127-EN). The total of 135 samples of different honey types has been examined. Five of them (3.7%) were positive to antibiotic residues. The presence of antibiotic residues was found in the acacia honey (0.31%), linden honey (0.33%), sunflower honey (0.19%), mixed honey (0.17%) and honeydew honey (0.10%). Such unprofessional, unconscionable and unlawful use of antibiotics leads to their presence in honey and other bee products, as well as in the highly desirable and valuable products making them unusable
Litters Health Status and Growth Parameters in the Sows Feeding Diets Supplemented with Probiotic Actisaf Sc 47Âź within Pregnancy Or Lactation
The aim of this study was to investigate the effect of supplementing standard diets for pregnant and lactating sows with live yeast culture (Saccharomyces cerevisiae) on their health status, as well as the health status and growth parameters of their litters during lactation. A total of 120 sows were divided into three groups: the first group was fed diets supplemented with probiotics during pregnancy (G+P, n=40), the second group was fed these diets during lactation (L+P, n=40), and the third group was the control group which was not fed diets supplemented with probiotics (C, n = 40). During the lactation period, a significantly (p<0.01) smaller proportion of probiotic treated sows (G+P=7.5%, L+P=12.5%) manifested clinical signs of the uterus and/or the udder disease in comparison with the control sows (22.5%). The incidence of infectious diarrhea in the nursing piglets was significantly (p<0.05) lower in the treated sows (12.5%) compared to the control sows (27.5 %). The average number of weaned piglets per litter (p/l) and average litter weight at weaning (lw) (G+P=11.6 p/l and 103.6 kg lw, L+P=11.1 p/l and 102.8 kg lw, C=10 p/l and 79 kg lw) were significantly higher (p<0.01 or p<0.05) in sows treated with probiotic compared to the control sows. These results clearly show that the use of probiotic significantly improves the health status of sows and nursing piglets, as well as the piglets growth parameters
The VMC Survey. XXXII. Pre-main-sequence populations in the Large Magellanic Cloud
Context
Detailed studies of intermediate- and low-mass pre-main-sequence (PMS) stars outside the Galaxy have so far been conducted only for small targeted regions harbouring known star formation complexes. The VISTA Survey of the Magellanic Clouds (VMC) provides an opportunity to study PMS populations down to solar masses on a galaxy-wide scale.
Aims
Our goal is to use near-infrared data from the VMC survey to identify and characterise PMS populations down to ⌠1 Mïżœ across the Magellanic Clouds. We present our colourâmagnitude diagram method, and apply it to a ⌠1.5 deg2 pilot field located in the Large Magellanic Cloud.
Methods
The pilot field is divided into equal-size grid elements. We compare the stellar population in every element with the population in nearby control fields by creating Ks/(YâKs) Hess diagrams; the observed density excesses over the local field population are used to classify the stellar populations.
Results
Our analysis recovers all known star formation complexes in this pilot field (N 44, N 51, N 148, and N 138) and for the first time reveals their true spatial extent. In total, around 2260 PMS candidates with ages . 10 Myr are found in the pilot field. PMS structures, identified as areas with a significant density excess of PMS candidates, display a power-law distribution of the number of members with a slope of â0.86 ± 0.12. We find a clustering of the young stellar populations along ridges and filaments where dust emission in the far-infrared (FIR) (70 ”m â 500 ”m) is bright. Regions with young populations lacking massive stars show a lower degree of clustering and are usually located in the outskirts of the star formation complexes. At short FIR wavelengths (70 ”m, 100 ”m) we report a strong dust emission increase in regions hosting young massive stars, which is less pronounced in regions populated only by less massive (. 4 Mïżœ) PMS stars
The VMC survey -- XXXVI. Young stellar variability in the Large Magellanic Cloud
Studies of young stellar objects (YSOs) in the Galaxy have found that a
significant fraction exhibit photometric variability. However, no systematic
investigation has been conducted on the variability of extragalactic YSOs. Here
we present the first variability study of massive YSOs in a region of the Large Magellanic Cloud (LMC). The aim is to
investigate whether the different environmental conditions in the metal-poor
LMC ( 0.4-0.5 Z_sun) have an impact on the variability characteristics.
Multi-epoch near-infrared (NIR) photometry was obtained from the VISTA Survey
of the Magellanic Clouds (VMC) and our own monitoring campaign using the VISTA
telescope. By applying a reduced -analysis, stellar variability was
identified. We found 3062 candidate variable stars from a population of 362 425
stars detected. Based on several Spitzer studies, we compiled a sample of
high-reliability massive YSOs: a total of 173 massive YSOs have NIR
counterparts (mag) in the VMC catalogue, of which 39
display significant () variability. They have been classified as
eruptive, fader, dipper, short-term variable and long-period variable YSOs
based mostly on the appearance of their band light curves. The
majority of YSOs are aperiodic, only five YSOs exhibit periodic lightcurves.
The observed amplitudes are comparable or smaller than those for Galactic YSOs
(only two Magellanic YSOs exhibit mag), not what
would have been expected from the typically larger mass accretion rates
observed in the Magellanic Clouds.Comment: Accepted for publication in MNRAS, 32 pages, 24 figure